Objective: Patients receiving mechanical ventilation through an endotracheal tube are at increased risk for pneumonia. Because microaspiration of contaminated supraglottic secretions past the endotracheal tube cuff is considered to be central in the pathogenesis of ventilator-associated and postoperative pneumonia, better sealing of the upper trachea by the endotracheal tube cuff could possibly reduce this risk. We therefore postulated that use of a polyurethane cuffed tube would prevent early postoperative pneumonia through this mechanism in a population of cardiac surgical patients.
Methods: In a prospective, single-blind, randomized study, patients scheduled for cardiac surgery were allocated to intubation with a polyurethane cuffed endotracheal tube or the routinely used polyvinyl chloride cuffed endotracheal tube. Patients were scheduled for routine or emergency cardiac surgery and admitted to an 8-bed cardiac surgical intensive care unit of a tertiary care hospital.
Results: A total of 134 patients were available for analysis (67 in each group). Whereas mortality was not different between the groups, the incidence of early postoperative pneumonia and empirical prescription of antibiotic therapy were significantly lower in the polyurethane group than in the polyvinyl chloride group (23% vs 42%, P < .03). Intensive care unit and hospital stays were not significantly different between the two study subsets (3 +/- 5 days vs 3 +/- 4 days and 16 +/- 9 vs 17+/-11 days, respectively). In a multivariate regression analysis, preoperative serum creatinine levels (odds ratio 1.85, confidence interval 1.02-3.37, P = .04) and perioperative transfusion (odds ratio 1.50, confidence interval 1.08-3.37, P = .015) were independently associated with increased risk of early postoperative pneumonia, whereas use of a polyurethane endotracheal tube was protective (odds ratio 0.31, confidence interval 0.13-0.77, P = .01).
Conclusion: Polyurethane cuffed endotracheal tubes can reduce the frequency of early postoperative pneumonia in cardiac surgical patients.